Ticks are obligate bloodsucking (so-called hematophagous) parasites, i.e., they cannot survive without blood. Larvae, nymphs and adults, both males and females need to suck blood. Adult hard tick females need a huge blood meal because they will need it for producing thousands of eggs: between 2'000 and 20'000, depending on the species. After their bloodmeal engorged adult female hard ticks can be 50 to 100 times larger than unfed.